Document FR-A-2 817 351 discloses a thermal accelerometer comprising a gas-filled enclosure containing a middle heater strand with detector strands extending on either side thereof, the resistivity of the detector strands being temperature sensitive. The detector strands are connected in a Wheatstone bridge together with constant resistances. The Wheatstone bridge is connected to a measurement circuit that delivers an electrical signal representative of a temperature difference between the detector strands. The temperature difference leads to an unbalance of the Wheatstone bridge and is representative of the acceleration to which the accelerometer is being subjected.
In order to increase the accuracy and the ability of the accelerometer to detect variations in acceleration at high frequencies, that document also proposes associating feedback strands with the detector strands, the feedback strands being disposed on either side of the detector strands and being fed with a feedback signal for compensating the temperature difference between the detector strands and for enabling the unbalance of the detector strands to be subjected to automatic zero control.
In a particular embodiment, it is stated that the feedback signals are applied to the feedback strands. Provision is also made for the feedback signals to be pulse signals that could be of variable width, but that in the embodiment described more particularly are pulse signals of constant width, thereby implying complex management of the feedback signals.